Technical Field
The present application relates to a knock determination apparatus for an internal combustion engine, and in particular to a knock determination apparatus for an internal combustion engine that performs knock determination by using an in-cylinder pressure sensor.
Background Art
There has been disclosed a control device for an internal combustion engine that performs knock control by using a knock sensor, in Patent Literature 1, for example. In the control device, vibration intensity values are calculated based on the output signals from the knock sensor, and a frequency distribution concerning the intensity values and the numbers (frequencies) of the respective intensity values is used in knock determination. More specifically, a median value V (50) and a standard deviation σ of the intensity values in the frequency distribution are calculated. Subsequently, a value obtained by adding 3σ to the median value V (50) is used as a knock determination level V (KD) for knock determination.